A place like the Right Livers' Rest was bound to draw freaks, same as molasses draws flies. 1935, George Goodchild, chapter 5, in Death on the Centre Court: By one o'clock the place was choc-a-bloc.
Swallowing certain types of poisons may cause excessive salivation. According to the National Library of Medicine, pesticides can cause excessive saliva when they are swallowed. Venom from snake bites or insect stings is another type of poisoning that can cause the malady.
Ulcer and more: Yes they can cause excessive saliva. These problems certainly warrant medical attention. See the doctor who did your testing or your family doctor to continue your diagnostic tests and give you proper treatment.